Construction method of tunnel entrance and exit hole

Abstract

The invention discloses a construction method of a tunnel entrance and exit hole. The construction method of the tunnel entrance and exit hole comprises the following steps that a hole top catchwateris excavated; the hole is excavated; a hole side slope and a heading slope are protected; a cover arch is constructed; and a pipe shed is constructed. When the hole top catchwater is excavated, excavation and laying are carried out sectionally from low to high. When the hole is excavated, hole excavation and side slope and heading slope excavation are carried out synchronously; an arc excavation reserved core native law is adopted in the hole excavation; and the side slope and the heading slope are excavated along a hole excavation line. The hole side slope and the heading slope protection process can be carried out following side slope and heading slope brushing. The cover arch construction working process comprises the following steps that surveying and setting out are carried out; the heading slope is excavated and excavation and supporting are carried out at the same time; an I-shaped steel arch frame is mounted; a template is mounted; and cover arch concrete is constructed. The pipe shed construction process comprises the following steps that hole site setting out and drilling machine erection are carried out; drilling hole footage and error correcting are carried out; pipe shed steel pipes are machined; the pipe shed steel pipes are jacked; and pipe shed slip casting is carried out. According to the construction method of the tunnel entrance and exit hole, the soft rock tunnel hole can be effectively reinforced.

Description

technical field [0001] The invention relates to a construction method for an entrance and exit opening of a tunnel. Background technique [0002] In recent years, the construction of highways and high-speed railways in my country has developed vigorously, and a large number of tunnel projects have been produced accordingly. Most highways and railways are generally routed along valleys, so shallow-buried bias tunnels account for a considerable proportion of these tunnel projects. Excavation of bias-pressure tunnel entrances has always been a major problem in the geotechnical engineering industry, especially in weak surrounding rock areas with complex terrain and geological environments. The stability is poor, the burial depth of the tunnel entrance section under bias pressure is extremely shallow, and the mountain is greatly disturbed during excavation, which is likely to cause problems such as tunnel side slope slides, tunnel collapse, lining cracks, and overall displacement...

AI Technical Summary

Problems solved by technology

Excavation of bias-pressure tunnel entrances has always been a major problem in the geotechnical engineering industry, especially in weak surrounding rock areas with complex terrain and geological environments. The stability is poor, the burial depth of the tunnel entrance section under bias pressure is extremely shallow, and the mountain is greatly disturbed during excavation, which is likely to cause problems such as tunnel side slope slides, tunnel collapse, lining cracks, and overall displacement of the tunnel, threatening the safety of tunnel excavators. safety, affect the normal operation of the tunnel, and bring serious hidden dangers to the safety of people's lives and property

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